4 • U. S. BUREAU OF FISHERIES. 



Special attention has been given to the fishes and the floating plants 

 and animals (plankton) that compose the food of the fishes, as 

 well as to the physical and chemical condition and the circulation 

 of the waters of the gulf. Several reports on special phases of the 

 survey have been published, but not until recently did the body of 

 data warrant undertaking a general account of the fish fauna. Dur- 

 ing the past year such an account has been completed by Dr. H. B. 

 Bigelow and is now in course of publication. 



The aim has been to prepare a handbook for the ready identifica- 

 tion of the fish occurring in the Grulf of Maine, and to present a 

 concise statement of what is known of the distribution of each, their 

 relative abundance, and the more significant facts in their life his- 

 tories. The descriptions have been made as simple as is compatible 

 with scientific accuracy, and are limited chiefly to such external 

 features as may suffice for identification in the field. As a further 

 aid to identification, keys to all species have been provided. The 

 area covered by the report includes the oceanic bight from Nan- 

 tucket and Cape Cod on the west to Cape Sable on the east, thus 

 including the shore lines of northern Massachusetts, New Hamp- 

 shire, Maine, and parts of New Brunswick and Nova Scotia. The 

 Gulf of Maine has a natural seaward rim formed by Nantucket 

 Shoals, Georges Bank, and Browns Bank, but the 150-fathom con- 

 tour has been taken as an arbitrary boundary because this includes 

 all the species apt to be caught by commercial fishermen. 



STUDIES IN FISH MIGRATIONS — TAGGING OPERATIONS. 



As a part of a plan to investigate the biology of the important 

 food fishes of the cod family (Gadidse), an extensive experiment in 

 tagging thtse fishes off the coast of New England had been inaug- 

 urated. The tagging is intended primarily to throw light on the 

 movements of the various species of fish between the different fish- 

 ing banks and between the banks and the shore. The bureau's 

 steamer Halcyon is being used for this work and has been outfitted 

 with appropriate fishing gear. The vessel left Gloucester for the 

 first tagging cruise on the 16th of April and the first tags were at- 

 tached on Nantucket Shoals. By June 30, 2,396 fish had been tagged. 

 It is planned to attach a total of not less than 10,000 tags during 

 the season. Cod, pollock, and haddock have been tagged, but by 

 far the greater number has been cod. Some few returns have been 

 obtained, but at this early date not even tentative conclusions can 

 be given. The work has been conducted mainly by William C. 

 Schroeder, with the advice and aid of Dr. H. B. Bigelow and Willis 

 H. Rich. 



The tags used are small and made of a noncorrosive metal so that 

 they will withstand the action of sea water, as it is expected that re- 

 turns will be obtained over a number of years. Each tag bears a 

 serial number and the initials U. S. B. F. As the fish are caught a 

 tag is attached, a record is made of its length, and the fish is then 

 released. A reward of 25 cents is being offered for each tag returned, 

 together with information as to when and where it was obtained. 



In addition to the tagging experiment there are being collected 

 material and data that will be used in other phases of the study of 

 the fishes, such as the rate of growth, spawning habits, and age at 

 maturity. 



